Contents

Introduction

The swsusp framework provides hibernation support on mainline kernels. This page discusses adding that functionality to ARM.

Motivation

Providing hibernation support for ARM provides several advantages:

Zero power consumption sleep

Snapshot boot ability

Shared effort with DDR self-refresh only suspend modes (such as RTC-only on am335x)

Utilizing the mainline swsusp framework also provides to uswsusp, allowing flexibility with where and how hibernation images are stored.

Challenges

The primary challenge to bringing hibernation to ARM is the complex state of PM within ARM, the large amount of CPU registers related to PM, and the complexity of saving and restoring those registers properly.

Patches

A set of patches is available for am335x hibernation, it is currently based on 3.8-rc5 plus some TI PM and am33xx patches.